Portal Vein Embolization

Indications for PVE

Commentator: RENÉ ADAM, MD

Comment:

PVE is used when the future remnant liver appears too small (ie, less than 30 percent of the total parenchyma when the patient has not received intensive chemotherapy or less than 40 percent, when the patient has received intensive chemotherapy). We try to prevent liver insufficiency postoperatively by performing PVE in a way that encourages hypertrophy of the liver that will be left in place.

Hypertrophy of the liver

Commentator: RENÉ ADAM, MD

Comment:

Hypertrophy of the liver occurs quickly. In Europe, we wait 1 to 1.5 months for the hypertrophy of the remnant liver before administering chemotherapy. We administer systemic therapy, but we wait two or three weeks for hypertrophy to be established because chemotherapy is antiregenerative, so the liver regeneration will be decreased. Afterwards, we reinitiate chemotherapy. It is a sort of compromise between not giving chemotherapy too soon and not waiting too long because you want to prevent a new recurrence, a new progression of the disease.

Indications for PVE in addition to chemotherapy

Commentator: RENÉ ADAM, MD

Comment:

Ideally, embolization is used when no lesions are present in the remnant liver. Unfortunately, in the majority of cases, a lesion often comes in contact with an important vessel of both lobes. When you occlude the portal system of the hemiliver, the other lobe will undergo hypertrophy because of growth factors, but growth factor may also act on the metastasis, possibly to a greater extent compared to the normal parenchyma. Therefore, you may perform hemihepatectomy without PVE if your remnant liver is sufficient.

Because the majority of patients have bilateral lesions, we first remove the lesion in the left liver, which is always less affected by the disease. At that time, we perform right PVE.

PVE

Commentator: MICHAEL CHOTI, MD

Comment:

If the liver is resectable, but not safe to resect because the remnant liver would be too small, we use a procedure called PVE, a technique that involves injecting material into the right portal vein — almost like chemoembolization. The injected gel clogs off the right portal vein, causing the right half of the liver to be stressed and to partially shrivel, and the left half of the liver, the part that wasn’t injected, to start growing to compensate for the damaged right half of the liver. We normally rescan the liver approximately four to five weeks after PVE and then recalculate the volume. If the liver is growing sufficiently, we proceed with the surgery. In it is not sufficient in size, we recalculate the volume a month later.

PVE

Commentator: JOHN PRIMROSE, MD

Comment:

PVE usually causes no symptoms, no toxicity. We can perform PVE as a day case or a single overnight stay in hospital. This could be accomplished during chemotherapy without the concern about the additive toxicity. We’ve had no problems at all, and I think most people who work in this area haven’t had any problems, so we can use both together. The patient will undergo PVE and, while we’re waiting for hypertrophy, the patient can receive chemotherapy. The best data on the time to hypertrophy are from Nick Groatae at MD Anderson. I think most of the hypertrophy occurs within a month, and it peaks within two months. If you combine PVE with chemotherapy, hypertrophy can take a little more than three months, so if you perform embolization shortly after the induction of the chemotherapy, the timing works out quite well.

PVE

Commentator: DANIEL HALLER, MD

Comment:

We don’t perform PVE at our institution, because frankly our surgeons don’t do it. We have a reasonably high volume, but we don’t have that high a volume. While I haven’t done a formal poll, I’ll bet no more than five or 10 institutions in the US perform this procedure and have enough experience doing it.

It always surprises me how quickly natural regeneration of the liver occurs. Within three to four months after liver resection, most patients will have enough regrowth of liver to allow for further surgery.